Multimedia can be of many different types, e.g. video, audio, still images, vector graphics. Typically, each kind of media has a native file format, depending on the format of the media, for storage in computer systems.
For multimedia, there also exist a large number of compression formats that utilize spatial and/or temporal redundancies in order to obtain a compressed format of the media. A video file may, for instance, be compressed according to the H.263 compression standard [1], an audio clip as AMR [2] or AAC [3], and an image as JPEG [4].
There exist today a number of different methods for storing and/or transmitting files in general, and more specifically media files. One known such method is to include the files in a so-called file container. Examples of such containers include TAR (Tape Archive) for UNIX systems and Zip-files. Although these can contain media files they lack control functions for presentations, synchronization with timed media, and the possibility to interleave media. Another known method is to include files as e-mail attachments, so-called multi-part MIME. Here it is possible to point at start location for a presentation, but otherwise the above limitations apply. There is also another kind of multimedia formats that don't store media files per se, but frame media content of certain media types. These formats lack the transparency and integrity of a container format that can store and recover media files. Examples of such multimedia formats include ASF (Advanced Streaming Format) and Flash.
The Third-Generation Partnership Project (3GPP) has standardized the 3GPP file format (3GP) [5] for carriage of timed multimedia (audio and video), based on the ISO base media file format [6]. It is used by the so called Multimedia Messaging Service (MMS) and the transparent end-to-end packet switched streaming service (PSS) for distribution of multimedia [9]. Moreover, streaming servers for serving streamed media can use 3GP files.